Submission #339995

#	Time	Username	Problem	Language	Result	Execution time	Memory
339995		Drew_	Cave (IOI13_cave)	C++14	100 / 100	1356 ms	640 KiB

cave

#include "cave.h"
#include <bits/stdc++.h>
using namespace std;

int const MAX = 5007;
int guess[MAX];
int comb[MAX];
int link[MAX];

void exploreCave(int N) {
	for (int i = 0; i < N; ++i)
		comb[i] = link[i] = -1;

	for (int gate = 0; gate < N; ++gate) //guessing which gate
	{
		for (int i = 0; i < N; ++i)
		{
			if (comb[i] != -1) guess[i] = comb[i];
			else guess[i] = 0;
		}

		int first_closed = tryCombination(guess);

		int lt = 0, rt = N-1;
		while (lt < rt)
		{
			int mid = (lt + rt) / 2;

			for (int i = 0; i < N; ++i)
			{
				if (comb[i] != -1) guess[i] = comb[i];
				else guess[i] = (i <= mid);
			}

			int closed = tryCombination(guess);
			if ((first_closed == gate) ^ (closed == gate)) rt = mid;
			else lt = mid + 1;

/*
			cerr << "guess: ";
			for (int i = 0; i < N; ++i)
				cerr << guess[i] << " ";
			cerr << '\n';

			cerr << "closed: ";
			cerr << closed << '\n';
*/
		}
		comb[lt] = first_closed == gate;
		link[lt] = gate;

		//cerr << "switch " << lt << " links gate " << gate << '\n';
		//exit(0);
	}

	answer(comb, link);
}

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24